Eiffel Tower,7th arrondissement, Paris, France

The Eiffel Tower is an iron lattice tower located on the Champ de Mars in Paris, France. It was named after the engineer Alexandre Gustave Eiffel, whose company designed and built the tower. Erected in 1889 as the entrance arch to the 1889 World's Fair, it was initially criticized by some of France's leading artists and intellectuals for its design, but has become both a global cultural icon of France and one of the most recognisable structures in the world. The tower is the tallest structure in Paris and the most-visited paid monument in the world; 6.98 million people ascended it in 2011. The tower received its 250 millionth visitor in 2010.

The tower is 324 metres (1,063 ft) tall, about the same height as an 81-storey building. Its base is square, 125 metres (410 ft) on a side. During its construction, the Eiffel Tower surpassed the Washington Monument to assume the title of the tallest man-made structure in the world, a title it held for 41 years, until the Chrysler Building in New York City was built in 1930. Because of the addition of the aerial atop the Eiffel Tower in 1957, it is now taller than the Chrysler Building by 5.2 metres (17 ft). Not including broadcast aerials, it is the second-tallest structure in France, after the Millau Viaduct.

The tower has three levels for visitors, with restaurants on the first and second. The third level observatory's upper platform is 276 m (906 ft) above the ground, the highest accessible to the public in the European Union. Tickets can be purchased to ascend by stairs or lift (elevator) to the first and second levels. The climb from ground level to the first level is over 300 steps, as is the walk from the first to the second level. Although there are stairs to the third and highest level, these are usually closed to the public and it is generally only accessible by lift.

Origin

First drawing of the Eiffel Tower by Maurice Koechlin including size comparison with other Parisian landmarks such as Notre Dame de Paris, the Statue of Liberty and the Vendôme Column.

The design of the Eiffel Tower was originated by Maurice Koechlin and Émile Nouguier, two senior engineers who worked for the Compagnie des Établissements Eiffel, after discussion about a suitable centrepiece for the proposed 1889 Exposition Universelle, a World's Fair which would celebrate the centennial of the French Revolution. In May 1884 Koechlin, working at home, made an outline drawing of their scheme, described by him as "a great pylon, consisting of four lattice girders standing apart at the base and coming together at the top, joined together by metal trusses at regular intervals". Initially Eiffel himself showed little enthusiasm, but he did sanction further study of the project, and the two engineers then asked Stephen Sauvestre, the head of company's architectural department, to contribute to the design. Sauvestre added decorative arches to the base, a glass pavilion to the first level, and other embellishments. This enhanced version gained Eiffel's support: he bought the rights to the patent on the design which Koechlin, Nougier, and Sauvestre had taken out, and the design was exhibited at the Exhibition of Decorative Arts in the autumn of 1884 under the company name. On 30 March 1885 Eiffel presented a paper on the project to the Société des Ingénieurs Civils; after discussing the technical problems and emphasising the practical uses of the tower, he finished his talk by saying that the tower would symbolise

"not only the art of the modern engineer, but also the century of Industry and Science in which we are living, and for which the way was prepared by the great scientific movement of the eighteenth century and by the Revolution of 1789, to which this monument will be built as an expression of France's gratitude."